Process for producing 2,3,3,3-tetrafluoropropene

ABSTRACT

The present invention discloses a manufacturing process to produce high purity 1234yf from 245eb, which preferably includes the removal of impurities present in 245eb raw material, the dehydrofluorination of 245eb, and the removal of impurities present in final crude product. The disclosed manufacturing process allows the production of a 1234yf product with lower the levels of 1225ye and/or trifluoropropene, preferably in amounts of less than about 500, and 50 ppm, respectively.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 12/510,740, filed Jul. 28, 2009, which applicationclaims the priority benefit of and incorporates herein by reference U.S.provisional application No. 61/085,141 filed Jul. 31, 2008. ApplicationSer. No. 12/510,540 also claims the priority benefit of as acontinuation-in-part and incorporates herein by reference U.S. regularpatent application Ser. No. 12/389,110, filed on Feb. 19, 2009, now U.S.Pat. No. 7,786,333, which in turn claims the priority benefit of U.S.regular application Ser. No. 11/588,464, filed Oct. 27, 2006, now U.S.Pat. No. 7,560,602, which in turn claims the priority benefit of U.S.provisional application No. 60/763,068, filed on Jan. 27, 2006 and60/733,355, filed on Nov. 3, 2005, each of which is incorporated hereinin its entirety by reference.

BACKGROUND

Field of Invention

The present invention relates to a processes for preparing2,3,3,3-tetrafluoropropane (1234yf).

Related Art

Chlorine-containing compounds, such as chlorofluorocarbons (CFCs), havebeen employed as refrigerants, foam blowing agents, cleaning agents,solvents, heat transfer media, sterilants, aerosol propellants,dielectrics, fire extinguishing agents, and power cycle working fluids.Such chlorine-containing compounds have proven to be detrimental to theEarth's ozone layer. Many of the hydrofluorocarbons (HFCs), used as thesubstitutes of CFCs, have been found to contribute to global warming.For these reasons, there is a worldwide effort to develop new compoundsthat are more environmentally benign while at the same time being aseffective, or more effective, from a performance standpoint.

Compositions containing fluorinated olefins, including particularly2,3,3,3-tetrafluoropropene (1234yf), are among the materials beingdeveloped for use in the aforementioned applications. In addition,2,3,3,3-tetrafluoropropene (1234yf) can be used as feedstock monomer forsynthesis of fluoropolymers and macromolecular compounds.

Methods for the production of 1234yf are known. For example, U.S. Pat.No. 7,560,602, which is assigned to the assignee of the presentinvention and which is incorporated herein by reference, discloses aprocess for producing 2,3,3,3-tetrafluoropropene (1234yf) by catalyticdehydrofluorination of 1,1,1,2,3-pentafluoropropane (245eb). While thispatent discloses a process having relatively high conversion andselectivity levels, and is therefore desirable and effective from thestandpoint, applicants have nevertheless come to appreciate that severaldisadvantages are associated with processes of the type disclosed inthis and similar patents. For example, the process disclosed in Exampleof 6 of this patent produces approximately three percent by weight ofcomponents that are described as being unknown. Applicants have come toappreciate that these byproducts can have a detrimental impact when usedin connection with one or more of the applications mentioned above.

Applicants have also come to appreciate the presence of such undesirablematerials in 2,3,3,3-tetrafluoropropene (1234yf) product can result, inat least certain cases, from the presence in the1,1,1,2,3-pentafluoropropane (245eb) feedstock of certain impurities.More particularly, applicants have come to also appreciate that certainmaterials available as a source of 245eb include other components thatcontribute, when used as feed stock source for the production of 1234yf,to a reaction product composition containing high levels ofcontaminants, including trifluoropropene and1,2,3,3,3-pentafluoropropene (1225ye). Applicants have come toappreciate that these and other materials can have a negative impact onthe resulting product. For example, the aforementioned materials areundesirable in the 1234yf product because of their undesirably highlevel of toxicity.

Applicants have found, especially in view of the deficiencies notedabove, improved processes for the production of 1234yf.

SUMMARY OF INVENTION

As mentioned above, applicants have found that for processes comprisingdehydrofluorination of 245eb to form 2,3,3,3-tetrafluoropropene(1234yf), even a small amount of certain impurities in the reactor feed,and in particular in the 245eb feed stock, can have a significantnegative impact on the desirability of resulting reaction product streamand/or 1234yf product, including particularly the purity of theresulting 1234yf. In particular embodiments, applicants have found thateven small amounts of hexafluorinated propanes in the reactor feed,including particularly 1,1,1,2,3,3-hexafluoropropane (236ea), and/orpentafluorinated propenes, including particularly1,2,3,3,3,-penatfluoropropene (1225ye), has a surprising andunexpectedly negative impact on the purity of the reaction product, andin particular the resulting 1234yf product.

Accordingly, one aspect of the invention provides methods for producing1234yf, and preferably high purity 1234yf product, from 245ebcomprising: (a) feeding at least one reactor feed stream containing245eb to a least one dehydrofluorination reactor and (b) ensuring thatsaid at least one feed stream contains not more than about 2% by weight,even more preferably not more than about 1% by weight, even morepreferably not more than about 0.5% of any one of the compounds1,1,1,2,3,3-hexafluoropropane (236ea) and 1,2,3,3,3,-penatfluoropropene(1225ye), based on the total weight of 245eb in the reactor feedstream(s).

In certain preferred embodiments, the methods comprise: providing a rawfeed stock comprising at least about 50% by weight of 245eb and aminority of one or more impurities selected from unsaturatedhalocarbons, including particularly 1225y and trifluoropropyne, 236ea,and 254eb; treating said raw feed stock, preferably by one or more ofthe steps of (i) subjecting said raw feed stock to a photochlorinationprocess; (2) distilling said raw feed stock; and liquid-liquidextracting said raw feed stock, to produce a purified feed stock whereinsaid purified feed stock comprises a reduced amount of at least one ofsaid impurities compared to said raw feedstock, preferably a reducedamount of the unsaturated halocarbon impurities compared to said rawfeed stock; and subjecting said high purify feed stock to conditionseffective to dehydrofluorinate at least a portion of said1,1,1,2,3-pentafluoropropane to produce a reaction product comprisingrelatively more 2,3,3,3-tetrafluoropropane compared to said high purityfeed stock.

In other embodiments, the methods comprise: providing a raw feed stockcomprising 245eb and one or more impurities selected from, unsaturatedhalocarbons, including particularly 1225ye and trifluoropropyne, 236ea,and 254eb, and; optionally subjecting said raw feed stock to aphotochlorination process to produce a modified feed stock comprising areduced amount of at least one of said impurities compared to said rawfeedstock, preferably a reduced amount of the unsaturated halocarbonimpurities compared to said raw feed stock; purifying said raw feedstock or said modified feed stock to produce a high purify feed stockdistillation and/or liquid-liquid extraction, wherein said high purityfeed stock comprises relatively less impurities compared to said rawfeed stock or said modified feed stock; subjecting said high purity feedstock to conditions effective to dehydrofluorinate at least a portion ofsaid 1,1,1,2,3-pentafluoropropane to produce a reaction productcomprising relatively more 2,3,3,3-tetrafluoropropane compared to saidhigh purity feed stock.

In certain preferred embodiments, the methods of the present inventionare carried out under conditions effective to produce a final productcomprising a majority of 2,3,3,3-tetrafluoropropane, from 0 to about 500part per million (ppm) of 1,2,3,3,3-pentafluoropropene and from 0 toabout 50 ppm of trifluoropropyne, which conditions optionally butpreferably include distilling said reaction product.

Another aspect of the invention provides a high purity2,3,3,3-tetrafluoropropene (1234yf) product containing from traceamounts to less about 500 part per million (ppm) of1,2,3,3,3-pentafluoropropene and from trace amounts to less than about50 ppm of trifluoropropene.

Unless specifically indicated otherwise herein, all amounts identifiedherein by percentage refer to percent by weight.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The present invention can be generally described as a process formanufacturing high purity 1234yf from 245eb. As mentioned above, acritical step according to one aspect of certain embodiments of theinvention comprises ensuring that the feed to the reactor in such aprocess contains not more than about 2% by weight of any one of thecompounds 1,1,1,2,3,3-hexafluoropropane (236ea) and1,2,3,3,3,-penatfluoropropene (1225ye), based on the total weight of245eb in the reactor feed stream(s). Applicants contemplate that in manyembodiments the ensuring step will involve treating a raw feedstockhaving an amount of one or more of these materials that is greater thanthe specified amount. However, it is also contemplated that in certainembodiments the ensuring step may comprise simply obtaining, for examplefrom outside sources, a 245eb feedstock having less than the specifiedamount of the indicated materials.

According to certain preferred embodiments, the methods comprise thesteps of:

(A) removal of impurities from the 245eb raw material (or raw feedstock) which, optionally but preferably, involves photochlorinating theunsaturates, such as 1225ye, present in the 245eb raw feed stock,preferably into 2,3-dichloro-1,1,1,2,3-pentafluoropropane, and/orinvolves distilling the 245eb feed to remove impurities such as 236 ea,1225ye, 2,3-dichloro-1,1,1,2,3-pentafluoropropane, etc. to obtain a highpurity 245eb feed,

(B) dehydrofluorinating the high purity 245eb feed, preferably in thepresence of a caustic solution in liquid phase or a catalyst in vaporphase into 1234yf, and

(C) optionally but preferably distilling the 1234yf reaction product tohave a final product concentration of 1225ye that is below 500 ppm,preferably below 200 ppm, and more preferably below 100 ppm, and a finalproduct concentration of trifluoropropyne that is below 50 pp.

A. The Removal of Impurities Included in 245eb Raw Material

In certain preferred embodiments, the unsaturated impurities such as1225ye are converted, prior to entering the 245eb dehydrofluorinationreactor, into corresponding saturated halogenated hydrocarbons havingincreased chlorine content, preferably via photochlorination in whichchlorine (Cl₂) reacts with the unsaturated impurities in the presence ofan ultraviolet light source. In one preferred photochlorination process,electromagnetic radiation, preferably light, from a suitable source isdirected through a reactor wall to interact with the reactants therein.The source of light may be, for example, any one of a number of arc orfilament lamps known in the art. Quartz or borosilicate glass such asPyrex glass may be employed as transparent material to construct theportion of the reactor wall through which the light passes and entersthe reactor. The photochlorination may be continuously carried out inthe gas phase, in which starting materials are vaporized and contactedwith chlorine vapor in a reaction zone. Although a wide range ofchlorination reaction conditions are believed to be suitable, in certainpreferred embodiments the reaction temperature is from about roomtemperature to about 50° C. Alternatively or additionally, thechlorination may be carried out in the liquid phase by feeding chlorineto a reactor containing starting materials, with it generally beingpreferred to control the reaction temperature below the boiling pointsof the starting materials and products.

The content of impurities such as 1225ye, 236ea, 254eb, and2,3-dichloro-1,1,1,2,3-pentafluoropropane in the 245eb raw feed may bereduced by any means known in the art, such as extraction and preferablydistillation. Although it is contemplated that a wide range ofseparation conditions can be used in accordance with the presentinvention, it is preferred in certain embodiments that the 245eb rawmaterials are distilled by passing at least a portion thereof through astandard distillation column and/or packed tower, or the like atatmospheric pressure, super-atmospheric pressure or a vacuum. Preferablythe pressure is less than about 300 psig, more preferably less thanabout 150 psig and most preferably less than 100 psig. The pressure ofthe distillation column inherently determines the distillation operatingtemperature for a given degree of separation. The 245eb may be recoveredas distillate by operating the distillation column at from about −10° C.to about 90° C., preferably from about 0° C. to about 80° C. Single ormultiple distillation columns may be used. In certain preferredembodiments, the purity of 245eb after distillation is at least about99.9% by weight.

B. The Dehydrofluorination of 245eb

The dehydrofluorination step can be carried out in a liquid phase in thepresence of a caustic solution or in a gas phase in the presence of adehydrofluorination catalyst. It is contemplated that the reaction canbe carried out batch wise, continuous, or a combination of these.

One preferred converting step involves a reaction in which 245eb iscontacted with a dehydrohalogenating agent, such as potassium hydroxide(KOH), sodium hydroxide (NaOH), Ca(OH)₂, CaO, and combinations of theseand/or other catalysts, to form a reaction product comprising2,3,3,3-tetrafluoropropene. This reaction may be described, by way ofillustration but not necessarily by way of limitation, by the followingreaction equation:CF₃CHFCH₂F+KOH→CF₃CF═CH₂+KF+H₂O

In preferred aspects of such embodiments, the dehydrohalogenating agentcomprises, and in certain embodiments consists essentially of, causticmaterial, such as KOH, and is preferably provided as an aqueous solutioncomprising from about 2% to about 100%, more preferably from about 5% toabout 90%, and even more preferably from about 10% to about 80% byweight of the caustic material, preferably comprising or consistingessentially of KOH.

In certain preferred embodiments, the caustic solution, and preferablythe KOH solution, is brought to a temperature of from about 20° C. toabout 100° C., more preferably from about 30° C. to about 90° C., andmost preferably from about 40° C. to about 80° C. The reaction pressurein such embodiments may vary, depending on particular processingparameters of each application. In certain embodiments, the reactionpressure ranges from atmospheric pressure, super-atmospheric pressure orunder vacuum. The vacuum pressure, when used, preferably in certainembodiments ranges from about 5 torr to about 760 torr.

Another preferred converting step involves a reaction in which 245eb iscontacted with a dehydrohalogenating catalyst, under conditionseffective to form a reaction product comprising of2,3,3,3-tetrafluoropropene and hydrogen fluoride. Thedehydrofluorination reaction may be conducted in any suitable reactionvessel or reactor, but it should preferably be constructed frommaterials which are resistant to the corrosive effects of hydrogenfluoride such as nickel and its alloys, including Hastelloy, Inconel,Incoloy, and Monel. These may be single or multiple tubes packed with adehydrofluorinating catalyst which may be one or more of halogenatedmetal oxides in bulk form or supported, metal halides in bulk form orsupported, and carbon supported transition metals, metal oxides andhalides. Suitable catalysts non-exclusively include fluorinated chromia(Cr₂O₃), fluorinated alumina (Al₂O₃), metal fluorides (e.g., CrF₃ andAlF₃) and carbon supported transition metals (zero oxidation state) suchas Fe/C, Co/C, Ni/C, Pd/C or transition metals halides. In a preferredembodiment of the invention, the 245eb is pre-vaporized or preheatedprior to entering the reactor. Alternatively, the 245eb is vaporizedinside the reactor. Useful reaction temperatures may range from about100° C. to about 600° C. Preferred temperatures may range from about150° C. to about 450° C., and more preferred temperatures may range fromabout 250° C. to about 350° C. The reaction may be conducted atatmospheric pressure, super-atmospheric pressure or under vacuum. Thevacuum pressure can be from about 5 torr to about 760 torr. Contact timeof the 245eb with the catalyst may range from about 0.5 seconds to about120 seconds, however, longer or shorter times can be used.

C. The Removal of Impurities Included in 1234yf Crude Product

2,3,3,3-tetrafluoropropene may be recovered from the reaction productmixture comprised of unconverted starting materials, product, andby-products including some or all of HF, 1234ze, 1225ye, andtrifluoropropyne by any means known in the art, such as extraction andpreferably distillation. In certain preferred embodiments, HF is removedor preferably recovered from the mixture of hydrogen fluoride andfluorocarbons prior to distillation. The removal of hydrogen fluoridemay be realized via acid-base neutralization in a caustic solutionscrubber. This may be conducted by running the product stream containinghydrogen fluoride and fluorocarbons through a caustic solution scrubberfollowed by a drying column. The recovering of hydrogen fluoride may beconducted in a gaseous phase by a continuous process of introducing astream of sulfuric acid to a stream of fluorocarbon and hydrogenfluoride. This may be conducted in a standard scrubbing tower by flowinga stream of sulfuric acid countercurrent to a stream of fluorocarbon andhydrogen fluoride. Sulfuric acid extraction is described, for example inU.S. Pat. No. 5,895,639, which is incorporated herein by reference. Themixture of 2,3,3,3-tetrafluoropropene, unconverted 245eb and any otherby-products are then passed through a distillation column. For example,the distillation may be preferably conducted in a standard distillationcolumn at atmospheric pressure, super-atmospheric pressure or a vacuum.Preferably the pressure is less than about 300 psig, more preferablyless than about 150 psig and most preferably less than 100 psig. Thepressure of the distillation column inherently determines thedistillation operating temperature. 2,3,3,3-tetrafluoropropene may berecovered as distillate by operating the distillation column at fromabout −10° C. to about 90° C., preferably from about 0° C. to about 80°C. Single or multiple distillation columns may be used. In certainpreferred embodiments, the levels of undesired 1225ye andtrifluoropropyne in the final 1234yf product may be below 500, and 50ppm, respectively.

EXAMPLES

The following examples serve to demonstrate that high purity 1234yf canbe produced through the process disclosed in the present invention.

Example 1 Purification of 245eb

A glassware set-up was used for purifying 245eb. The distillation flaskwas cooled with wet ice and was then charged with 3.00 kg of 88.1% 245ebcrude feed. A couple of boiling chips were added into the flask to aidboiling. After reattaching the flask, the liquid was heated to causedistillation. The progress of the distillation was followed by measuringthe temperature of the vapor at the top of fractionation column and byanalyzing the compositions of periodically collected distillates. 245ebwas collected during the period when its 245eb concentration was 99.9%.In the end, 1.73 kg of purified feed was obtained.

Example 2 245eb Dehydrofluorination in Caustic Solution

To a 50 gallon agitated reactor about 300 pounds of 245eb is chargedinto this vessel that contains a 20% molar excess of 25% KOH. A packedcolumn with a condenser is also installed on top of the reactor, whichis used to reflux the unreacted 245eb and relatively pure 1234yf istaken off at the exit of the condenser. The reaction is conducted at atemperature of 60° C. and the pressure is allowed to increase to about190 psig and the product is taken off overhead as the reaction proceeds.Analysis of the product shows a 95.0% conversion of the 245eb and aselectivity of 96.9% to 1234yf.

Example 3 245eb Dehydrofluorination in the Presence of a Catalyst

A Monel tube reactor (0.75″OD×0.625″ID×23.0″L) was charged with 20 cc ofcatalyst pellets. The reactor was heated by a 12″ split tube furnace. Amulti-point thermocouple, inserted through catalyst bed, was used tomeasure the temperatures at the bottom of catalyst bed and at the top ofcatalyst bed. A purified 245eb feed (>99.9%) was passed through catalystbed at a rate of 6 g/h (grams/hour). The effluent was analyzed by anon-line GC to determine 245eb conversion and 1234yf selectivity.

As shown in Table 1, the fluorinated Cr₂O₃ provided a 245eb conversionof about 99% and a selectivity of about 97% to 1234yf at 240-320° C.,and the fluorinated MgO provided a 245eb conversion of about 98% and aselectivity of about 99% to 1234yf at 300-410° C.

TABLE 1 245eb dehydrofluorination over fluorinated metal oxide catalystsTemp. Conversion Selectivity Selectivity, Bottom-Top 245eb 1234yf othersCatalyst (°) (%) (%) (%) Fluorinated Cr₂O₃ 240-320 98.9 96.9 3.1Fluorinated MgO 300-410 97.8 98.8 1.2

Example 4 Purification of 1234yf

Approximately 100.0 lbs of 1234yf crude product is charged into adistillation still, which consists of a 10 gallon reboiler, 2 inch ID by10 feet propack column, and a shell and tube condenser. The column hasabout 30 theoretical plates. The distillation still is equipped withtemperature, pressure, and differential pressure transmitters. Thedistillation is run at a pressure of about 85 psig. The distillate issampled and analyzed by GC at regular intervals. 1234yf is collectedduring the period when its 1234yf purity is ≧99.9%. In the end, 75.5 lbsof purified product is obtained. GC analysis of the final productindicates it contains 100 ppm of 1225ye and 10 ppm of trifluoropropyne.

What is claimed is:
 1. A method for producing 2,3,3,3-tetrafluoropropene(1234yf) from 1,1,1,2,3-pentafluoropropane (245eb) comprising: (a)providing a stream containing at least about 50% by weight of 245eb andat least one impurity in an amount greater than 2% by weight, whereinsaid impurity is selected from 1,1,1,2,3,3-hexafluoropropane (236ea) and1,2,3,3,3-pentafluoropropene (1225ye); (b) processing said steamprovided in step (a) to produce at least one reactor feed stream byensuring that said at least one reactor feed stream contains not morethan 2% by weight of any one of the compounds1,1,1,2,3,3-hexafluoropropane (236ea) and 1,2,3,3,3,-penatfluoropropene(1225ye), based on the total weight of 245eb in the reactor feedstream(s); and (c) feeding at least a portion of said feed stream to atleast one dehydrofluorination reactor to produce a reaction productcomprising relatively more 2,3,3,3-tetrafluoropropene compared to theamount of 2,3,3,3-tetrafluoropropene in said feed stream.
 2. The methodof claim 1 wherein said ensuring step comprises ensuring that said atleast one reactor feed stream contains not more than about 0.5% byweight of any one of the compounds 1,1,1,2,3,3-hexafluoropropane (236ea)and 1,2,3,3,3,-penatfluoropropene (1225ye), based on the total weight of245eb in the reactor feed stream(s).
 3. The method of claim 1 whereinsaid ensuring step comprises treating said 245fa feed stream to reducethe content of at least one of said 1,1,1,2,3,3-hexafluoropropane(236ea) and 1,2,3,3,3,-penatfluoropropene (1225ye).
 4. The method ofclaim 3 wherein said treating step comprises subjecting said 245eb feedstream to one or more of the steps of (i) photochlorination; (ii)distillation; and (iii) liquid-liquid extraction.
 5. The method of claim4 wherein said treating step comprises subjecting said 245eb feed streamto distillation, liquid-liquid extraction, or combinations of these. 6.The method of claim 1 wherein said method produces a 1234yf productcomprising not more than about 500 part per million (ppm) of1,2,3,3,3-pentafluoropropene and not more than about 50 ppm oftrifluoropropene.
 7. The method of claim 1 wherein said at least oneimpurity in an amount greater than 2% by weight is selected from1,1,1,2,3,3-hexafluoropropane (236ea) and 1,2,3,3,3-pentafluoropropene(1225ye) and further comprising processing said reaction product toproduce a high purity 1234yf product comprising not more than about 500part per million (ppm) of 1,2,3,3,3-pentafluoropropene and not more thanabout 50 ppm of trifluoropropyne.
 8. A method for producing2,3,3,3-tetrafluoropropene (1234yf) from 1,1,1,2,3-pentafluoropropane(245eb) comprising: (a) providing a raw feed stock comprising a majorityof 1,1,1,2,3-pentafluoropropane and greater than 2% by weight of one ormore impurities selected from, 1,2,3,3,3-pentafluoropropene (1225ye) and1,1,1,2,3,3-hexafluoropropane (236ea); (b) optionally, subjecting saidraw feed stock to a photochlorination; (c) purifying said raw feed stockor said modified feed stock to produce a high purity feed stock, whereinsaid purifying involves a distillation and/or a liquid-liquid extractionprocess and wherein said high purity feed stock comprises relativelyless of at least one of said impurities compared to said raw feed stockor said modified feed stock; (d) subjecting said high purify feed stockto conditions effective to dehydrofluorinate at least a portion of said1,1,1,2,3-pentafluoropropane to produce a reaction product comprisingrelatively more 2,3,3,3-tetrafluoropropane compared to said high purityfeed stock; and (e) processing said reaction product to produce a finalproduct comprising a majority of 2,3,3,3-tetrafluoropropane, and notgreater than about 500 part per million (ppm) of1,2,3,3,3-pentafluoropropene and not greater than about 50 ppm oftrifluoropropene.
 9. The method of claim 8 wherein saidphotochlorination is not optional and involves reacting1,2,3,3,3-pentafluoropropene with Cl₂ in presence of ultraviolet lightto yield 2,3-dichloro-1,1,1,2,3-pentafluoropropane.
 10. The method ofclaim 8 wherein said high purity feed stream comprises at least about99.9 weight percent 1,1,1,2,3-pentafluoropropane.
 11. The method ofclaim 8 wherein said dehydrofluorination involves contacting said highpurify feed stream with at least one dehydrohalogenation agent selectedfrom the group consisting of KOH, NaOH, Ca(OH)₂, and CaO.
 12. The methodof claim 8 wherein said dehydrohalogenation agent comprises an aqueoussolution.
 13. The method of claim 8 wherein said dehydrofluorinationinvolves contacting said high purity feed stock with at least onedehydrohalogenation catalyst.
 14. The method of claim 8 wherein said rawfeed stock comprises greater than 2% by weight of1,2,3,3,3-pentafluoropropene (1225ye) and wherein said final productcomprises from 0 to about 200 part per million of1,2,3,3,3-pentafluoropropene.
 15. The method of claim 14 herein saidfinal product comprises from 0 to about 100 part per million of1,2,3,3,3-pentafluoropropene.